Thread drag tester



Jan. 13, 1953 w. P. IRELAND, JR 2,625,040

THREAD DRAG TESTER Filed July 27, 1950 2 SHEETS-@SHEET 1 J 1953 w. P. IRELAND, Ji 2,625,040

THREAD DRAG TESTER Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE 6 Claims.

The present invention relates to processes of testing thread for frictional drag and to thread drag testers.

A purpose of the invention is to provide an accurate measure of frictional drag of thread, especially as a basis of determining sewability.

A further purpose is to provide a means for testing the effectiveness of thread lubricants and treating compositions.

A further purpose is to progress thread forwardly at a uniform speed, desirably approximating the maximum thread speed in machine sewing, to press opposed drag surfaces against opposite sides of the moving thread under measured loads and to apply increments of increased load to the drag surfaces desirably until the thread breaks in tension.

A further purpose is to load a circular drag surface against a fiat drag anvil with the thread interposed between.

A further purpose is to mount one of the drag surfaces, preferably the circular drag surface, on an arm pivoted back of the drag surfaces in the direction of thread motion.

A further purpose is to load the drag surfaces by a pull rod urged downwardly by a pivoted load rocker which is loaded by a weight.

A further purpose is to move the weight along the load rocker by a chain, and desirably to manipulate the chain from a sprocket shaft below the load rocker pivot.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate one only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoint of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Figure 1 is a side elevation of the machine of the present invention with the front cover removed and part of the weight slider broken away.

Figure 2 is a top plan view of Figure 1.

Figure 3 is an enlarged fragmentary section on the line 3-3 of Figure 2.

Figure 4 is a left hand elevation of Figure 3 omitting the forward Winding reel.

Figure 5 is a right end elevation of Figure 2, omitting the rear guide roller.

Figure 6 is a fragmentary sectional plan of Figure 1 on the line 6-6.

Figure 7 is a left end elevation of Figure 6, showing the frame in section.

In the drawings like numerals refer to like parts throughout.

Describing in illustration but not in limitation and referring to the drawings, wherever refer.- ence is made herein to thread it is intended to include any similar material whethe designated as thread, yarn, warp, weft or the like, and whether it consists of fibers, continuous filament or otherwise.

The tests of the character to which the present invention is applicable are believed to find their widest application in connection with thread used for sewing, although it will be understood that they are also of importance in connection with thread used for weaving, knitting and other textile operations.

It has been found that the effectiveness of sewing and other thread depends not only upon the tensile strength, but upon the uniformity of properties and especially of cross section, and upon the frictional drag of the thread. Mere tests of tensile strength or of uniformity do not correlate well with performance characteristics in sewing and other operations, and experience indicates that a yarn of lower tensile strength may be more sewable than a yarn of higher tensile strength where the former yarn has lower frictional drag.

The testing of frictional drag of thread is not only important in the determination of the properties of the thread itself, but is also very useful to determine the relative merits of various thread lubricants and other textile treating compositions. Tests of this character can be made in accordance with the present invention by testing the same thread before treatment with a given textile treating composition and then after treatment with different textile treating compositions. The test can also be performed on thread which has been treated by a textile treating composition and from which the textile treating composition has been extracted or otherwise removed.

Existing methods of testing thread do not agree well with practical experience as to the sewability of the thread, and one of the important aspects of the invention is that improved correlation is obtained between actual test results and practical sewability experience with the thread. It is thus possible to purchase thread not only by weight and tensile strength, but by frictional drag which indicates sewability, and it is possible to specify lubrication and other liquid treatments on the basis of the resulting frictional drag and corresponding sewability.

In accordance with the invention, the thread under test is progressed forward at a speed which and side walls 23.

is uniform and which is desirably standardized at a value approximating the maximum speed of machine sewing. I have found it desirable to employ a speed of forward progression of yards per minute, which corresponds to a comparatively high sewing speed. It will be understood that other speeds of progression can be used and that any test results reported should include a report of the speed of progression.

In accordance with the invention, the thread, while progressing forwardly at the particular chosen speed, is subjected to lateral pressure between drag surfaces. The drag pressure is increased by increments of load, and the Zload application desirably continues .until failure takes place. As soon as failure occursfthe'load is removed and the test is repeated .on another length of thread until several readings have been obtained, the average being the result/reported.

The drag surfaces preferably consist of a longitudinally extending anvil and a circular or cylindrical surface loaded against this anvil.

The machine is supported and mounted on a box-like base 20,'having a top 2|, a'bottom 22 The box frame has a back 24 and a removable front 25.

The thread 26 under test is withdrawn'from any suitable'source, 'suchas a'spool 21, and is guided 'in its path through the machine by a rotatable circumferentially' recessed guide'rollZB rotatably supported in a bearing bracket '30 from a block 3| on the'top of the frame, and then by a guide finger 32 having a downwardly directed guide notch 33 supported on one of the side arms '34 pivoted at35 on the block 3|. At'thc forward end, the thread is wound around a take-up .reel 36, which turns in a direction to wind up the yarn on a shaft 31 rotated at the predetermined speed by a combined variable speed electric rotor andspeed reducer 38, supported .on a bracket 40 from the frame.

The arms .34 are cross connected by a spacer .4l interconnected with the arms by screws 42.

At the ends forwardlyof the pivot 35, the arms 34 mount an upper frictional drag .element 43 desirably in the form of a cylinder as'best seen in Figure 3, and rigidly mounted to the arms and restrained against rotation. In other words, though the frictional drag element is in the .form of a roller, it is not permitted to roll. The frictional drag element 43 is above the thread and cooperates with the .lower frictional drag element 44 mounted on the top of block 3| and desirably effectively a straight .anvil or plate, which is conveniently beveled at-45 at the approaching and leaving edges to avoid abrasive action. 'It hasbeen found best to employ smooth hardened steel'surfaces for both the drag cyl- .inder and the drag anvil, the surfaces desirably being machined or polished to a smoothness which is at least RMS 25.

Load is applied to the drag cylinder by pull rods 46 pivotally mounted at 41 by clevises 48 at the outer ends of the axis of the drag cylinder 43. The pull rods pass through slots 50 inthe top 2i of the frame, and at the lower ends are cross connected by a pivot 5|. The pivot 5| makes pivotal connection in an opening 52 of a generally horizontal load.rocker '53 which extends on opposite sides of the pivotal connection at 52. The load rockerlha s an upward extending lug 54 at one side of the pivotal connection 52, which has an opening which "engages knife edgepivot '55 supported in brackets depending from the top of the frame. The knife edge pivot 55 thus provides fixed pivotal support for the load rocker.

The load rocker has a generally horizontal track or guideway 5'! which receives guide rollers 58 pivotally mounted on a slider 60 which supports a load weight 6!. It will be evident that the load weight is on the opposite side of pivotal connection 5| of pull .rods 45 from the fixed pivot at .knife edge 55.

The slider is suitably manipulated along the .rocker interior guideway 51 as by chain 62 connected at one point to the slider at 63 and supported at-one end by a driving sprocket 64 and .at the other end by an idler sprocket 65, both suitably journalled on the load rocker. The driv- ..ing;:sprocket:64rhas on the same shaft and suitably on the opposite side of the load rocker, a sprocket 66 which supports one end of an adjusting chain 67. The other end of adjusting chain 67 is supported and turned by sprocket 68 which is on shaft 10 journalled in the adjustment rocker and carrying adjustment nob H at the front of the frame. A suitable slot 72, allowing adequate freedom, permits the adjustment shaft to pass through the front 25.

An important aspect of the invention is the placement of adjustment shaft 18 immediately below knife edge pivot 55 in the loaded position so that any hand load applied to nob ll during adjustment will'not create error in the loading of the-"thread.

"Theposition of the slider along the load rocker at anygiven time may be observed on a scale 12 to indicate the load, the scale being viewed through any suitable slot or window in the front of the machine. The scale may be calibrated in any desired units such as pounds, kilograms, ounces etc.

In operation the weight is first moved to the right in Figure '1. The thread 25 to be tested is looped-aroundguide roller 28 and then carried through notch 33 of guide 32 and started around the wind-up reel, suitably tying the thread to the ree'lor engaging it in the notch or opening as well known for starting thread on a spool. The motor and speed reducer -38 are then started to wind up the thread on the reel at the standard speed, and then the first increment of load is applied by moving the weight toward the left in Figure 1. Assuming that no break occurs, successive increments of load are applied while the thread continues to travel between the load elements at the standard or any desired speed. If it is merely desired to determine that th frictional drag properties are low enough for a particular use, it may be sufficient in a particular "test simply to load the thread up to a certain percentage above the specification value and determine that it does not break under these conditions. 'The more usual method of operation is to continue loading until the thread breaks, and then repeat the test several times, in each case recording the load at which the thread breaks in tension. The final results will then usually be averaged in making the report, although the individual results or the maximum deviation may also be reported as an indication of th uniformity of the thread.

It'will'be evident that the invention provides a very simple, reliable and effective manner of testing the frictional drag of thread.

The invention can be applied with various types of loadingmechanism, the weight loading mechanism shown being preferred to spring loading mechanisms which can be used in the invention because of the increased accuracy.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the process and structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. Th process of testing thread, which comprises progressing the thread forward at a uniform speed, pressing opposed circular and straight longitudinal surfaces against opposite sides of the moving thread under measured loads, and increasing the load against the thread until it breaks in tension.

2. The process of testing thread, which comprises progressing the thread forward, pressing opposed drag surfaces against opposite sides of the moving thread, and applying increments of increased load to the drag surfaces against the thread until it breaks.

3. In a thread drag tester, means for forwardly progressing thread under test, a friction anvil extending longitudinally along one side of the thread, a pivoted arm having a portion extend- 1 ing in the direction of progression, a curved friction loading element mounted on the arm forward in the direction of progression of the pivot and movable toward and away from the thread and the anvil and means for applying a measured load to the arm.

4. In a thread drag tester, means for forwardly progressing thread under test, a friction anvil extending longitudinally along one side of the thread, a pivoted arm having a portion extending in the direction of progression, a curved friction loading element mounted on the arm forward in the direction of progression of the pivot and movable toward and away from the thread and the anvil, a pull rod pivotally connected to the arm forwardly of the pivot and depending below the arm, a load rocker pivotally mounted below the arm, extending generally horizontally and pivotally connected to the pull rod at one side of the pivot of the load rocker, and a weight movable along the load rocker on the side of the pivotal connection of the pull rod remote from the load rocker pivot.

5. In a thread drag tester, means for forwardly progressing thread under test, a pair of friction drag elements engaging the thread on opposite sides, an arm supporting one of the drag elements, a pivot for the arm back of the drag elements in the direction of thread motion, a pull rod pivotally connected to the arm forward of its pivot, a load rocker pivotally connected to the .pull rod below the drag elements and intermediate the ends of the load rocker, a pivot for the load rocker to one side of the pivotal connection to the pull rod, a track running generally horizontally in the load rocker on the opposite side of the pivotal connection to the pull rod from the load rocker, a weight movable in the track, pivoted sprockets on the load rocker at opposite ends of the track, a chain extending around the sprockets and connected to the weight, and adrive for one of the sprockets.

6. In a thread drag tester, means for progressing the thread under test, a pair of friction drag elements engaging the thread on opposite sides, an arm supporting one of the drag elements, a pivot for the arm back of the drag elements in the direction of thread motion, a pull rod pivotally connected to the arm forward of its pivot, a load rocker pivotally connected to the pull rod below the dra elements and intermediate the ends of the load rocker, a pivot for the load rocker to one side of the pivotal connection to the pull rod, a track running generally horizontally in the load rocker on the opposite side of the pivotal connection to the pull load from the load rocker pivot, a weight movable in the track, an adjustment shaft positioned rotatably on the load rocker below the load rocker pivot, a sprocket on the adjustment shaft, a sprocket shaft at one end of the track pivotally mounted on the load rocker, two sprockets on the sprocket shaft, a first chain interconnecting the sprocket on the adjusted shaft with one of the sprockets on the sprocket shaft, a sprocket pivotally mounted on the load rocker at the opposite end of the track from the sprocket shaft and a second chain mounted over the second sprocket on the sprocket shaft and the sprocket on the load rocker at the opposite end of the track and interconnected with the weight.

WILLIAM P. IRELAND, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 379,088 Wallwork Mar. 6, 1888 2,121,149 James June 21, 1938 2,285,255 Davis June 2, 1942 2,378,614 Zahn June 19, 1945 FOREIGN PATENTS Number Country Date 394,184 Great Britain June 22, 1933 954,235 France June 6, 1949 

